But here’s a scheme that’s focused not on closing the digital divide but on borrowing its power source.

Five million people die each year because of a lack of available energy infrastructure – either from vaccine-preventable diseases or unclean water, say Harvey Rubin and Alice Conant in New Scientist.

They say maintaining the cold chain for vaccines “can be an overwhelming challenge” – a 2007 study found that 90% of local health centers in rural India suffered frequent power failures and only 45% had backup power.

Their solution is to harness the surplus power from mobile networks to refrigerate vaccines or to purify water. “If we succeed, by 2015 everybody in the world could have access to vaccines and clean water and we could save 5 million lives a year,” the authors say.

The GSMA, the operators’ association, is already on-board with its Community Power program. The GSMA estimates that by 2012 639,000 off-grid cell towers will be in operation in the developing world – “a potential new energy infrastructure in locations with no access to the electrical grid.”

It is a great idea and, you wonder if it is not a pointer to a new business line for cellcos as an off-grid micro-utility in rural Africa and Asia.